UFCThe Ultimate Fighting Championship (UFC) is a U.S.-based mixed martial arts organization, recognized as the largest MMA promotion in the world. The UFC is headquartered in Las Vegas, Nevada and is owned and operated by Zuffa, LLC. This promotion is responsible for solidifying the sport's postion in the history-books.
UFC is currently undergoing a remarkable surge in popularity, along with greater mainstream media coverage. UFC programming can now be seen on FOX, FX, and FUEL TV in the United States, as well as in 35 other countries worldwide.

I asked a bunch of fighters and mma personalities on twitter this question. Ive gotten 2 answers so far. Big John said "Got 2 B between Chuck or Randy". Renzo Gracie said "I would burn a fuse in my head if I try it" I guess he meant it would be way too difficult to do the MMAth on this. lol.

I wouldn't pick Chuck now because I'm going by fighters in their current condition. Chuck's chin is gone, Tito's midsection is a mess, and Ken is just a mess so unless they draw each other in a matchup I would pick against them.

I think Coleman is still in fighting shape, and he was fairly competitive on his way out, better than some of the others.

Coleman was tough in his day, but with all due respect by today's standard, is a hack.